As anyone who’s sat through painful political dinner-party conversation knows, there seems to be a direct relationship between the volume of a person’s voice and the wrongness of their facts. This appears to be true of not just political views, but opinions on genetically modified foods as well. A new study published this week in the London-based journal Nature Human Behaviour found that people most opposed to GMOs (stands for “genetically modified organisms”) not only are the least knowledgable about their science, but those same critics report knowing the most—a winning combination.

In a nationally representative survey of 2,000 American adults, researchers from American and Canadian universities asked respondents to rank, on a scale of 1 to 10, how concerned and how opposed they are to genetically modified foods. They were then asked how confident they felt in their knowledge of science and genetics. Finally, the adults were presented with questions about basic science and genetics, such as “True or false: Ordinary tomatoes do not have genes, whereas genetically modified tomatoes do.”

Analyzing the findings, researchers concluded that “We find that as extremity of opposition to and concern about genetically modified foods increases, objective knowledge about science and genetics decreases, but perceived understanding of genetically modified foods increases.” Put even more simply: People who know the least think they know the most, and are more often wrong about scientific facts.

This is problematic news for scientists, who have stated that they find foods containing genetically modified ingredients to be no less safe than those made with ingredients modified by “conventional” techniques. Even as scientists advance this message, the percentage of consumers who say they avoid foods made with GMOs has increased from 15 percent in 2007 to 46 percent in 2018.

While the survey’s findings may be disheartening, they’re not entirely surprising: “This result is perverse, but is consistent with previous research on the psychology of extremism,” Phil Fernbach, the study’s lead author and a professor of marketing at University Of Colorado Boulder, said in a release. “Extreme views often stem from people feeling they understand complex topics better than they do.”